Briefing Magento Knowledge

which two of these methods should you implement?

You want to display a grid for a custom collection. After extending Mage_Adminhtml_Block_widget_Grid, which
two of these methods should you implement? (Choose two)

A.
_getCollection ( )

B.
_prepareCollection ( )

C.
_prepareColumns ( )

D.
toHtml ( )

E.
render ( )